Repair of holes and cracks in clay sewer pipe

ABSTRACT

The repair of a sewer line having a fracture, and employing a liner sleeve and an elastomer sleeve extending about the line sleeve, and a filler slurry, includes: 
     (a) installing the liner sleeve and the elastomer sleeve endwise in the sewer line to locate the two sleeves in bridging relation with the fracture, and 
     (b) displacing slurry into a space formed between the two sleeves to cause the elastomeric sleeve to expand and seal against the sewer line in bridging relation with the fracture.

This is a division of application Ser. No. 600,893, filed Apr. 16, 1984.

BACKGROUND OF THE INVENTION

This invention relates generally to repair of sewer lines, and more particularly to simple and effective apparatus and method to inexpensively repair such lines.

In the past, fracturing of clay pipe lines necessitated digging up the line along its length, removing the old pipe, installing new pipe, and filling in the dirt and repairing the overlying road surface. This was a very expensive operation, and one that hardly warranted such expense and effort where the clay pipe line was fractured in only a few places.

SUMMARY OF THE INVENTION

It is a major object of the invention to provide method and apparatus to repair such lines without digging up the line, thus saving great expense and effort.

Basically, the method employs a liner sleeve and elastomer sleeve extending about the liner sleeve, and a filler slurry, and includes the steps:

(a) installing the liner sleeve and said elastomer sleeve end wise in the sewer line to locate the two sleeves in bridging relation with the fracture, and

(b) displacing slurry into a space formed between the two sleeves to cause the elastomeric sleeve to expand and seal against the sewer line in bridging relation with the fracture.

The slurry is typically displaced radially through the liner sleeve into the space between the sleeves and via a fixture which is releasably attached to the liner sleeve to travel therewith in the sewer line, the fixture being detachable from the liner sleeve and recoverable after slurry displacement is accomplished.

Further, a drag system may be employed to drag the two sleeves endwise in the sewer line to the fracture location, and the drag system may then be released for recovery thereof. The positioning of the drag cable may be correlated to the position of a scanning camera used to preliminarily locate the fracture, whereby the position of the fracture may be accurately determined so that the elastomer sleeve may accurately bridge the fracture.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:

DRAWING DESCRIPTION

FIG. 1 is a vertical elevation, in section, showing details of installation of a liner and elastomer sleeve unit;

FIG. 2 is an enlarged elevation, in section, showing details of a puller unit;

FIG. 3 is an enlarged vertical elevation showing details of a fluid connector releasably attached to a liner and sleeve unit;

FIG. 4 is a section, in elevation, on lines 4--4 of FIG. 3;

FIG. 5 is a fragmentary plan view on lines 5--5 of FIG. 3;

FIG. 6 is an enlarged vertical elevation showing sealing off of a fracture in a clay pipe line, employing the liner and sleeve unit;

FIG. 7 is an enlarged fragmentary section showing a flow smoothing ring on the liner and sleeve unit;

FIG. 8 is an enlarged fragmentary section showing end-to-end interconnection of two liner and sleeve units; and

FIG. 9 is a view like FIG. 6, showing application to a branching clay pipe line.

DETAILED DESCRIPTION

Referring first to FIG. 1, sewer line 10 has clay pipes 11 laid end-to-end, under the ground surface 12. When one or more of the pipes develops a fracture, as at 13, the problem of how to economically repair the line is presented.

In accordance with the invention, a liner and elastomer sleeve "pig" unit 14 is employed, and is introduced underground, or via first manhole 15, well 16, and the clay pipe line, to be traveled endwise therein to the location of the fracture. See FIG. 1, showing a puller cable 17. The latter is first introduced downwardly in well 16, through the pipe line 10, and run up second well 16a through manhole 15a to winch 18 on a vehicle or truck 19. As winch 18 is rotated by motor and drive 21, the cable 17 is pulled endwise, to pull unit 14 underground and along the pipe line to the location of the fracture. That location may first be determined as by a television camera 22 advanced endwise by the cable in line 10. Idler drums 23-26 and associated frames 23a-26a may first be installed in and above the wells 16 and 16a, as shown, so that the unit 14 may be pulled endwise down well 16, around drum 24, and endwise in the pipe line 10, and so that the cable will travel in the same manner, as well as up well 16a, around drum 26, and onto the winch 18. The length of the cable 17 extended when camera 22 locates the fracture may be noted and used to subsequently register the unit 14 across the fracture.

The unit 14 may be attached to the cable as by a tubular container shell 28 closely fitting endwise within the bore 29a of a liner sleeve 29 of unit 14 (see FIG. 2). The wall 28a of shell 28 is shown as of bellows shape, to expand and grip bore 29a in response to air pressurization of the shell interior 28b, air supplied via hoses 30 and 30a extending from a surface pressure source 31, and controlled by valve 32. When the valve 32 is closed, pressurization of bellows wall 28a ceases, and cable 17 and container 28 may be pulled free of the installed unit 14, as by operation of winch 18. A snap release connection of the air hose 30a to container wall 28a is shown at 33.

The unit 14 also includes an elastomer sleeve 34 attached to and extending about the liner sleeve 29, as for example as shown in FIGS. 1 and 6. Metallic bands 35 and 36 at opposite ends of the unit 14 annularly hold the ends of the elastomer sleeve tightly and sealingly against the circular surface of the lower sleeve, and in travel mode, the elastomer sleeve 34 fits closely about a cylindrical surface 29b of sleeve 29, between the bands.

FIG. 6 shows the unit having arrived at the fracture in the clay pipe sewer line. It is brought into bridging relation with the fracture, as shown. At that point, slurry 37 is displaced into a space between the sleeves and under pressure, to cause the sleeve 34 to expand outwardly and seal against the bore 11a of the sewer line pipe that is fractured, to establish an annular seal against the bore and bridging the fracture. Thereafter, the liquid contents of the line flow through the liner piper 29, which becomes anchored to the sewer line due to the liner 34 expanding into the fracture and held there by hardening of the slurry 37 in the space 38. Typical slurries include resin which polymerizes in situ in space 38, as for example epoxy resins, and grout, and a catalyst if required.

FIGS. 3-6 show means for feeding slurry and grout components in two lines or hoses 40 and 41, and a catalyst in hose 42, extending from the surface to the unit 14. These components are fed together or blended in a mixer fitting 43 (see FIG. 5), and then fed in a bore 44 upwardly at 44a and through an attachment fitting 45 into space 38. Fitting 45 may be a grease type fitting thread connected to the wall of liner 29, as at 46. See also surface control valves 40a 41a and 42a.

Mixture fitting 43 is releasably connected to wall fitting 45, so that fitting 43 can be removed, i.e. pulled free of the unit 14, after slurry delivery to space 38. As shown, the duct 44a is within a short stroke plunger 50 urged upwardly by air pressure to grip the lower end 45a of the fitting 45, as during travel of unit 14 into FIG. 6 position, and during delivery of slurry components into space 38. Such air pressure, delivered by hose 30, is exerted upwardly against a piston 51 slidable in cylinder 52, and connected to plunger 50. At such times as disconnection and retrieval of the fitting 43 and associated apparatus is desired, the air pressure is shut off, as by closure of the valve 32, which causes the plunger 50 to release from the fitting 45. The fitting 43 may then be pulled leftwardly in FIG. 3, so that the fixture 45 lower end flange 45b slides out of a slot 54 in fixture 43, the latter then being pulled out of the sewer by operation of winch 55 reeling the hoses 30, and 40-42.

FIG. 7 shows an elastomer or rubber ring 56 attached to the forward traveling end of the unit 14, and having a flaring bore 56a, to cause sewer liquids to flow into the interior 14c of unit 14, as unit 14 travels rightwardly in FIG. 7. Note that the annular outer edge 56b of ring 56 travels closely adjacent the bore 11a of the sewer line clay pipe 11.

FIG. 8 shows the use of an elastomer annulus 59 fitting over the end of one unit 14d and over the end of a previously installed unit 14e to establish a seal therebetween. When unit 14d is pulled toward and endwise against unit 14e, the annulus 59, installed on either unit, fits over the other unit.

FIG. 9 shows a modified unit 14f, like unit 14, but having a side opening 60 to register with a branch passage 61 in a clay pipe 62. 

I claim:
 1. The method of repairing a sewer line having a fracture, and employing a liner sleeve and an elastomer sleeve extending about the liner sleeve, and a flowable hardenable filler, that includes:(a) installing the liner sleeve and said elastomer sleeve endwise in the sewer line to locate the two sleeves in bridging relation with the fracture, and (b) displacing said flowable filler between the two sleeves to cause the elastomeric sleeve to expand and seal against the sewer line in close bridging relation with the fracture, and (c) allowing the filler to harden, between said sleeves.
 2. The method of claim 1 wherein said elastomeric sleeve is attached at opposite ends thereof to the liner sleeve, and said (b) step includes displacing said filler radially through said liner sleeve.
 3. The method of claim 2 including pre-locating the position of said fracture, and dragging said liner sleeve with said elastomeric sleeve attached thereto endwise in said sewer line.
 4. The method of claim 1 wherein the filler contains two components which, when mixed, cause hardening of the slurry, and said (b) step includes mixing said components at the installed location of said sleeves within the sewer line.
 5. The method of claim 2 including installing a second liner sleeve and elastomer sleeve combination in said sewer line so that the second liner sleeve extends in sealed end-to-end relation with said first mentioned liner sleeve.
 6. The method of claim 1 wherein said filler consists of polymerizable resin and grout.
 7. The method of claim 1 including preliminarily clamping the elastomer sleeve to the liner sleeve at opposite ends of the latter.
 8. The method of claim 1 including providing a filler delivery system including elongated hose means extensible underground to deliver said filler, maintaining said system releasably clamped to the liner sleeve during and (a) and (b) steps, subsequently releasing the delivery system from the liner sleeve, and retrieving said system from the sewer line.
 9. The method of claim 8 including using fluid pressure to maintain said releasable clamping.
 10. The method of claim 1 including providing a fluid pressure responsive pull system, and maintaining said pull system releasably connected to the liner sleeve while pulling said liner sleeve endwise in the sewer line.
 11. The method of claim 10 including releasing said pull system from the liner sleeve after said (a) step is accomplished.
 12. The method of claim 1 including preliminarily scanning said sewer line to locate said fracture, and measuring the distance to said fracture so as to enable controlled bodily displacement of said sleeves into bridging relation with the fracture. 